install rails in mac code example

Example: install ruby and rails on mac

brew install rbenv ruby-build

# Add rbenv to bash so that it loads every time you open a terminal
echo 'if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi' >> ~/.zshrc
source ~/.zshrc

# Install Ruby
rbenv install 2.6.6
rbenv global 2.6.6
ruby -v